The present invention involves a synthetic process to produce the known antibiotic oxazinomycin. Oxazinomycin also known as minimycin is a known C-nucleoside antibiotic, see, for example, T. Haneishi et al., J. Antibiotics, 24, 797 (1971) and K. Sosaki et al., J. Antibiotics, 25, 151 (1972). The antibiotic is known to be produced by several species of Streptomyces when utilized in a fermentation, see, for example, the above references and also Gutowski et al., Ann. N.Y. Acad. Sci., 255, 544 (1975). The antibiotic inhibits growth of both gram positive and gram negative bacteria and has demonstrated activity against transplantable tumors.
The starting material for the novel process is a compound of the formula ##STR1## wherein R.sub.1 and R.sub.2 are hydrogen or hydroxy but are different and R.sub.3 is a group of the formula ##STR2## WHEREIN R.sub.4 is hydrogen, lower alkyl, lower alkoxy, halo or nitro and R.sub.5, R.sub.6 and R.sub.7 are lower alkyl and R.sub.9 is hydrogen or lower alkyl and is the same.
The starting material of formula II wherein R.sub.3 is a trityl moiety, i.e. ##STR3## is known; see, for example, H. Ohrui et al., Tetrahedron Lett., 1951, (1973). The starting material of formula II wherein the trityl moiety is substituted may be made in an analogous manner as that disclosed in the Ohrui et al. reference. The novel process of the present invention is set forth in the following reaction scheme: ##STR4##